<!DOCTYPE html>
<html lang="en" xmlns:v-on="http://www.w3.org/1999/xhtml">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
    <script src="https://cdn.jsdelivr.net/npm/vue"></script>
</head>
<body>
<div id="vue">
    <button v-on:click="sayHi">点我</button>
</div>

<script type="text/javascript">
    var vm = new Vue({
        el: '#vue',
        data: {
            message: 'Hello Vue!'
        },
        methods:{
            sayHi: function (event) {
                alert(this.message);
            }
        }
    });
</script>
</body>
</html>